AUT. 19 AMERICAN" MUSCOID FLIES ALDRICH 15 



Legs yellow; middle and hind femora, and sometimes the front 

 ones, infuscated on the apical third or more; middle and hind tibiae 

 decidedly infuscated; all the tarsi black, the middle femora ap- 

 proximately twice as long as the hind ones, longer than the entire 

 head and body of the insect; their tibiae are only a little shorter 

 and the tarsi are also much elongated, about equal to the femur. 

 The length of the middle legs is subject to some variation. The 

 front and hind legs are moderately elongated, with long tarsi. Front 

 pulvilli much elongated, the others less so. 



Wings distinctly and rather evenly infuscated, the fourth vein 

 with an oblique rounded bend, thence slightly concave, ending barely 

 before the extreme tip of the wing. The apical cell rather narrowly 

 open. The wing is considerably elongated and narrowed, but not 

 so much so as in some related species. There is no costal spine ; the 

 third vein has several hairs at base, sometimes extending halfway to 

 the cross vein. The first vein is distinctly hairy on the apical part, 

 beginning where the auxiliary vein diverges from it; the basal por- 

 tion frequently shows two or three scattered hairs, rarely more. 



Length, 7 mm. 



Female. — Body, legs, and wings all much shorter than in male, 

 head rounder, the front 0.26 of head width; third antennal joint 

 infuscated from near the base. Front legs entirely yellow, except 

 tarsi ; middle and hind femora with a trace of inf uscation and their 

 tibiae rather distinctly brown. Tarsi black. Wings as in the male, 

 but shorter and broader. Abdomen yellow at base, the black oc- 

 cupying all of the third and fourth segments and about half of the 

 second, in the middle extending forward almost to the first. The 

 second, third, and fourth segments with broad silvery crossbands 

 at base. 



Length. 6 mm. 



The description of the male is drawn from the Brazilian specimens, 

 that of the female from a specimen in the L'nited States National 

 Museum collected at San Kafael, Vera Cruz, by C. H. T. Townsend; 

 the National Museum has three additional males from the Tropics, 

 from Frontera, Tabasco (Townsend) ; Cayuga, Cruatemala (Schaus 

 and Barnes) ; and Higuito, San Mateo. Costa Rica (Pablo Schild). 

 Our only tropical female is the one described above. 



The United States National Museum also contains specimens from 

 the United States M^hich are apparently of the same species. Four 

 of these were reared at French Creek, W. Va., by F. E. Brooks, as 

 parasites of the species of the weevil genus Balamnus. One is from 

 Mound, La., reared in 1897 from Conotmchelus juglamdis. Other 

 specimens are from Washington, D. C. ; Peaks of Otter, Va. ; Lexing- 

 ton, Ky. ; Lawrence, Kans. ; La Fayette, Ind. ; and Dawson Camp, 

 Salt River. Ariz. ; collectors being R. C. Shannon, J. M. Aldrich, Wil- 



